discourse/vendor/assets/javascripts/div_resizer.js

/**
  This is a jQuery plugin to support resizing text areas.

  Originally based off text area resizer by Ryan O'Dell : http://plugins.jquery.com/misc/textarea.js

  @module $.fn.DivResizer
**/

var div, endDrag, grip, lastMousePos, min, mousePosition, originalDivHeight, originalPos, performDrag, startDrag, wrappedEndDrag, wrappedPerformDrag;
div = void 0;
originalPos = void 0;
originalDivHeight = void 0;
lastMousePos = 0;
min = 230;
grip = void 0;
wrappedEndDrag = void 0;
wrappedPerformDrag = void 0;

startDrag = function(e, opts) {
  div = $(e.data.el);
  div.addClass('clear-transitions');
  div.blur();
  lastMousePos = mousePosition(e).y;
  originalPos = lastMousePos;
  originalDivHeight = div.height();
  wrappedPerformDrag = (function() {
    return function(e) {
      return performDrag(e, opts);
    };
  })();
  wrappedEndDrag = (function() {
    return function(e) {
      return endDrag(e, opts);
    };
  })();
  $(document).mousemove(wrappedPerformDrag).mouseup(wrappedEndDrag);
  return false;
};

performDrag = function(e, opts) {
  var size, sizePx, thisMousePos;
  thisMousePos = mousePosition(e).y;
  size = originalDivHeight + (originalPos - thisMousePos);
  lastMousePos = thisMousePos;
  size = Math.min(size, $(window).height());
  size = Math.max(min, size);
  sizePx = size + "px";
  if (typeof opts.onDrag === "function") {
    opts.onDrag(sizePx);
  }
  div.height(sizePx);
  if (size < min) {
    endDrag(e, opts);
  }
  return false;
};

endDrag = function(e, opts) {
  $(document).unbind("mousemove", wrappedPerformDrag).unbind("mouseup", wrappedEndDrag);
  div.removeClass('clear-transitions');
  div.focus();
  if (typeof opts.resize === "function") {
    opts.resize();
  }
  div = null;
};

mousePosition = function(e) {
  return {
    x: e.clientX + document.documentElement.scrollLeft,
    y: e.clientY + document.documentElement.scrollTop
  };
};

$.fn.DivResizer = function(opts) {
  return this.each(function() {
    var grippie, start, staticOffset;
    div = $(this);
    if (div.hasClass("processed")) return;
    div.addClass("processed");
    staticOffset = null;
    start = function() {
      return function(e) {
        return startDrag(e, opts);
      };
    };
    grippie = div.prepend("<div class='grippie'></div>").find('.grippie').bind("mousedown", {
      el: this
    }, start());
  });
};